Does the community welcome engineering physics question? e.g.
- How to build an AOM driver with a DDS board?
- What is an Evaluation Board?
- How to using AD9915 chips to build a ~400 MHz AOM driver?
In general, questions asking how to build electronic devices are off topic here. There are a couple exceptions:
The questions you propose in your post don't seem to meet these criteria, so I would consider them off topic. They may fit on Electrical Engineering or Signal Processing, as dmckee pointed out in a comment.
The Physics Meta question Experimental Physics and Engineering shows that this community's view is that there is no objective distinction between experimental physics and engineering and that whether a particular engineering question is suitable for Physics Stack Exchange is a matter of asking
What kind of person is most likely to have the answer?
It is not possible to provide a definitive answer to your general question. Your particular question could be on-topic if you identified some knowledge which this community is likely to have. In the absence of any explanation of what you were finding difficult about your project, I voted to close your question because it seemed to me that somebody with expertise in assembling circuit boards was most likely to provide the help which you require.
You were clearly aware of the RF output requirements, and even had your own ideas about how to do it (DDS board, Evaluation Board, AD9155 chips). Suitable circuit designs are easily found on the internet. It seemed to me that you probably needed advice about choosing between different designs, selecting suitable components, and then assembling, soldering and testing the circuit. I think you are more likely to get such advice from a community of electrical/electronics engineers who have expertise in doing this for a wide variety of projects than from a community of physicists which majors on answering conceptual questions.
When your question is closed it is common to be offended and to take it personally. A more helpful response is to recognise it as saying "Sorry, we are unlikely to be able to help you. We don't want to waste your time. Try this other site instead."
I notice that you have re-posted the question on Electronics SE as I advised, but it has been closed there also, as being too broad. It would have suffered the same fate had it remained on this site. The quality of your question is at least as important as the topic you are asking about.
I notice also that you have not provided any further information as requested by that community. If you show little or no effort to define what exactly your difficulty is, to look for an answer yourself, and to engage with those who ask for more information, then you are unlikely to get an answer wherever you post your question. See What does everyone mean by "Insufficient research effort"?